We are investigating psychological mechanisms underlying use, learning, and comprehension in children and adults. The theoretical organization derives in large part from generative transformational linquistics: modern linquistic theory provides a powerful description of language structure and suggests approaches to a psychology of language use and acquisition. Current work suggests the notion of meta-linguistic processing as an account of certain speaker skills in making syntactic and semantic judgments and in decoding aspects of reading. More specifically, the research is designed to approach four main issues: (1) processes and strategies underlying language acquisition; (2) innovative features of linguistic organization, in both use and acquisition; (3) extralinguistic factors in language use and learning; particularly, memory, recall, and cognitive capacity, and (4) the problem of reading acquisition.